Engine Fuse keeps blowing

Try disconnecting the starter solenoid control lead and see if it still blows the fuse when no engine crank while switch in start position.

Try disconnecting the alternator and see if symptoms change.

You might also try using a 12V test lamp (or better, a headlamp) in place of the fuse. It may not crank but it allows you to low power circuits without blowing fuses. Observe lamp brightness as you go from run to start. Brightness is relative to current flow.

Comment for further assistance.

May be a bad fan or thermal switch not working. The a/c condenser sits in front of the radiator. It may be that the load on the engine going up the mountain is too much for just the air blowing across it to keep it cool, and the car shuts the a/c off to try and keep engine temp down. Cruising along on level ground is enough to keep things cool. Going up the mountain means more engine heat and probably reduced speed, which reduces air flow, especially if a fan isn't working.
Let car cool off, start engine and let it warm up without driving. Monitor temp and fans. When temp gets about normal, look for fan to kick on. Then when turning on a/c, look for the other fan to kick on. Don't let engine overheat. If one or both fans don't come on, start there. Check fan motor not locked up, relay working, fuse/wiring good.

Like blowing a fuse in a house, the fuse in the car is blowing because there is a short somewhere or there is too much current trying to flow thru the circuit.
You would need to check that circuit for a short to ground.

Hi Eason, The fuse which keeps blowing is the ECU fuse, which means the computer isn't working. That being so, the vehicle will will not start. The starter motor problem is separate and will need the starter relay or the solenoid replaced. The fact that the fuse for the management system keep blowing means there is a short or overload of that system which must be detected urgently! (WITH ALL DUE HASTE...IF NOT SOONER) in other words it may be dangerous if you have a short, as it can cause a fire! Get it sorted asap. Regards John

Unplug the wiper motor and replace the fuse. If it works the wiper motor is shorted out. It may also be the wiring rubbed thrue somewhere causing a short.

that fuse powers pcm fuel heater and some other things. when the fuse blows the pcm shuts down. causing it to not run. usually its the heater that is bad. it is located at the back driver side by the fuel pump. you can unplug it and see if it starts. if so you will need to replace the heater

Sounds like the fuel pump is shorted.

at least 90,000 kilometers

tnx 4 using fixya,

drcool
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check the wire harness to the ecm... which is located under the radio... if you , like I , live in a wet / snowy climate... the water /ice from your boots melts and collects near the harness. Maybe it corroded a wire and is causing it to short?

You have a wire rubbing on something metal. Look at the wiring harness in the car and engine compartment. Try moving them around a bit and see if you can get the fuse to blow or not to blow.